adding a question field to CCK

Hello drupalers;

I am building a schools website where i want teachers to ask students question form time to time.
I used CCK module to build a content type.
i dont want to give the teachers permission to add a new content type anytime they want to ask a new question.

I want to create a content type like "questionnaire" and give the teachers permission to create "Questionnaire".

When a teacher creates a questionnaire, there will be a field for the question where he/ she will type the question. Of course the normal CCK module takes care of something this.

What i want is this, as students views the Questionnaire created by his / her teacher, they should be able to type in their response and even upload files to backup their response.

Please note that i dont want the students to use comment to supply their answer and i do not want to use webform for this.

How can i go about this, i believe there should be a special CCK field module that can take care of this.

Thanks